The Government's plans to squeeze welfare budgets will be "pretty brutal", TUC general secretary Brendan Barber has warned.

Mr Barber told a fringe event at the Liberal Democrat conference that he is "extremely fearful" of the cuts that will be unveiled in next month's Government spending plan.

Treasury Chief Secretary Danny Alexander told the event in Liverpool that "fairness" is always a factor as he makes the decisions that will be announced in the comprehensive spending review.

Mr Barber said: "I'm extremely fearful of what the consequences of the cuts that are now being planned are going to be. I'm fearful in quite a number of areas. I'm fearful that we might be about to see pretty major and pretty brutal changes to our welfare system."

He criticised the language used by ministers including Chancellor George Osborne to describe those on benefits.

"When I hear George Osborne talking about lifestyle choices that need to be taken away from them and so on I think the tone of that I find very worrying, indeed very offensive.

"We have got two-and-a-half million people unemployed at the moment, one million young people desperately trying to find work. The problem that they have got, they haven't made a lifestyle choice that they don't want to work, the problem they've got is that there aren't enough jobs in the economy."

Mr Barber said forecasts indicate the cuts will mean 600,000 jobs lost in the public sector and 700,000 in the private sector.

By making public spending cuts 80% of the effort to reduce the deficit, with only 20% tackled by raising taxes, Mr Barber said the Government risks being "massively socially regressive".

Mr Alexander said: "There's a very strong Liberal Democrat case for reforming our welfare system. I think one of the most catastrophic failures of the last Labour government was its failure to reform welfare. What I can promise is that our belief in fairness is something that will be in my mind every day I'm making these decisions."